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1.
Abstract Dimer and trimer adenylates with 2′-5′ phosphorothioate linkages were synthesized via the phosphoramidite method using p-nitrophenyl-ethyl group for phosphate protection and followed by sulfur oxidation. The various diastereoisomers were separated and characterized. 相似文献
2.
Intact hepatopancreocytes were obtained from hibernating or active purinotelic snails, H. pomatia (Gastropoda). When incubated with [14C]glycine or [14C]formate, they synthesized de novo purine compounds, including also adenylates, adenosine and adenine. Hepatopancreocytes resynthesized also adenylates and other purine compounds from [3H]adenine or from [3H]adenosine split by the H. pomatia cell enzyme to adenine; the resynthesis of ADP+ATP was proportional to adenine concentration. Thus all reactions of the postulated adenine cycle: AMP leads to adenosine leads to adenine leads to AMP occur in the intact hepatopancreocytes; this cycle could probably be responsible for maintenance of the high level of adenylates during winter sleep. 相似文献
3.
Abstract Reaction of isatoic anhydride with adenosine, adenosine 5′-phosphate, oligoribonucleotides or with the E. coli tRNAVal led to attachment of an anthraniloyl residue at 2′-or 3′-OH groups of 3′-terminal ribose residue. No protection of the S'-hydroxyl group or internal 2′-hydroxyl groups is required for this specific reaction. Anthraniloyl-tRNA which is an analogue of aminoacyl-tRNA forms a ternary complex with EF-Tu*GTP. The anthraniloyl-residue is used as a fluorescent reporter group to monitor interactions with proteins. 相似文献
4.
Hiroshi Ashihara Claudio Stasolla Natalia Loukanina Trevor A. Thorpe 《Physiologia plantarum》2000,108(1):25-33
In order to examine the biosynthesis, interconversion, and degradation of purine and pyrimidine nucleotides in white spruce cells, radiolabeled adenine, adenosine, inosine, uracil, uridine, and orotic acid were supplied exogenously to the cells and the overall metabolism of these compounds was monitored. [8‐14C]adenine and [8‐14C]adenosine were metabolized to adenylates and part of the adenylates were converted to guanylates and incorporated into both adenine and guanine bases of nucleic acids. A small amount of [8‐14C]inosine was converted into nucleotides and incorporated into both adenine and guanine bases of nucleic acids. High adenosine kinase and adenine phosphoribosyltransferase activities in the extract suggested that adenosine and adenine were converted to AMP by these enzymes. No adenosine nucleosidase activity was detected. Inosine was apparently converted to AMP by inosine kinase and/or a non‐specific nucleoside phosphotransferase. The radioactivity of [8‐14C]adenosine, [8‐14C]adenine, and [8‐14C]inosine was also detected in ureide, especially allantoic acid, and CO2. Among these 3 precursors, the radioactivity from [8‐14C]inosine was predominantly incorporated into CO2. These results suggest the operation of a conventional degradation pathway. Both [2‐14C]uracil and [2‐14C]uridine were converted to uridine nucleotides and incorporated into uracil and cytosine bases of nucleic acids. The salvage enzymes, uridine kinase and uracil phosphoribosyltransferase, were detected in white spruce extracts. [6‐14C]orotic acid, an intermediate of the de novo pyrimidine biosynthesis, was efficiently converted into uridine nucleotides and also incorporated into uracil and cytosine bases of nucleic acids. High activity of orotate phosphoribosyltransferase was observed in the extracts. A large proportion of radioactivity from [2‐14C]uracil was recovered as CO2 and β‐ureidopropionate. Thus, a reductive pathway of uracil degradation is functional in these cells. Therefore, white spruce cells in culture demonstrate both the de novo and salvage pathways of purine and pyrimidine metabolism, as well as some degradation of the substrates into CO2. 相似文献
5.
Stanislaw F. Wnuk Johanna D. Stoeckler Morris J. Robins 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):389-403
Abstract Adenosine derivatives lacking a 5′-hydroxyl group seldom act as alternative substrates of adenosine deaminases from calf intestine and other mammalian sources. A deaminase from Aspergillus oryzae deaminated adenosine 5′-thioether derivatives cleanly and more efficiently than alkyl nitrites. The inosine derivatives were very poor alternative substrates and weak inhibitors of purine nucleoside phosphorylase. 相似文献
6.
F. Trischitta M. G. Denaro C. Faggio M. Mandolfino T. Schettino 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,166(1):30-36
The regulation of salt absorption in the sea water cell intestine was studied by evaluating the effects of theophylline, 8 Br cyclic adenosine monophosphate, 8 Br cyclic guanosine monophosphate, atriopeptin III, porcine vasoactive intestinal peptide and prostaglandin E
1 on the short-circuit current, the transepithelial voltage difference and conductance and on the dilution potentials. It was shown that theophylline increased the transepithelial conductance and reduced the magnitude of the dilution potentials, indicating that the drug increase the anion conductance of the tight junctions. In addition its inhibitory effect on short-circuit current and transepithelial voltage difference suggests that theophylline also affects the transcellular transport mechanisms. It was shown that 8 Br cyclic guanosine monophosphate and 8 Br cyclic adenosine monophosphate affect transcellular mechanisms underlying Cl– transport since both compounds reduced short-circuit current and transepithelial voltage difference; however, cyclic adenosine monophosphate is less effective since unlike cyclic guanosine monophosphate, even at maximal concentration, it was not able to completely abolish transepithelial voltage difference and short-circuit current. The effects of cyclic guanosine monophosphate and cyclic adenosine monophosphate were not additive even if cyclic guanosine monophosphate may produce further inhibition of ion transport in 8 Br cyclic adenosine monophosphate-treated tissues. In addition, cyclic guanosine monophosphate but not cyclic adenosine monophosphate reduced the magnitude of the dilution potentials, suggesting that cyclic guanosine monophosphate acts also on the paracellular pathway. Rat atriopeptin III, a peptide known to increase cyclic guanosine monophosphate cellular levels, behaved like 8 Br cyclic guanosine monophosphate since it lowered the dilution potentials and reduced short-circuit current and transepithelial voltage difference to near zero values, suggesting that the hormone modulates both paracellular and transcellular transport mechanisms, probably acting on the Na-K-2Cl cotransport. Agents acting via cyclic adenosine monophosphate, like porcine vasoactive intenstinal peptide and prostaglandin, behaved like 8 Br cyclic adenosine monophosphate. They were less effective in inhibiting ion transport and did not interfere with the paracellular pathway.Abbreviations
AP III
rat artriopeptin III
-
8 Br cAMP 8
Br cyclic adenosine monophosphate
-
8 Br cGMP 8
Br cyclic guanosine monophosphate
-
g
t
transepithelial conductance
-
I
sc
short circuit current
-
IC
50
half-maximal inhibitory concentration
-
NaK ATPase
Na-K-adenosine monophosphate
-
NPPB
5-nitro-2-(3-phenylpropylamino)-benzoic acid
-
PGE
prostaglandin E
1
-
R
t
tissue resistance
-
SITS
4-acetamide-4-isothiocyano-stilbene-2,2-disulfonic acid
-
V
t
transepithelial voltage difference
-
VIP
porcine vasoactive intestinal peptide 相似文献
7.
Moon Woo Chun Sung Wook Choi Tae Kyung Kang Won Jun Choi Hea Ok Kim Zhan-Guo Gao 《Nucleosides, nucleotides & nucleic acids》2013,32(4):408-420
On the basis of high binding affinity of 3′-aminoadenosine derivatives 2b at the human A3 adenosine receptor (AR), 3′-acetamidoadenosine derivatives 3a–e were synthesized from 1,2:5,6-di-O-isopropylidene-D-glucose via stereoselective hydroboration as a key step. Although all synthesized compounds were totally devoid of binding affinity at the human A3AR, our results revealed that 3′-position of adenosine can only be tolerated with small size of a hydrogen bonding donor like hydroxyl or amino group in the binding site of human A3AR. 相似文献
8.
Michael E. Perlman 《Nucleosides, nucleotides & nucleic acids》2013,32(1):73-82
Abstract The 2′-deuterio arabino analogs of tubercidin and adenosine have been prepared by Swern oxidation of the 3′,5′-TPDS derivatives of tubercidin and adenosine and reduction with NaBD4. Subsequent inversion of stereochemistry at C-2′ yielded [2′-2H]tubercidin and [2′-2H]adenosine with 98% deuterium incorporation. 相似文献
9.
Claudia Piazza Fernando Formaggio Marco Crisma Claudio Toniolo Johan Kamphuis Bernard Kaptein Quirinus B. Broxterman 《Journal of peptide science》1999,5(2):96-102
Trikoningin KB II, a ten‐amino acid residue lipopeptaibol blocked at the N‐terminus by the n‐octanoyl group and at the C‐terminus by the 1,2‐amino alcohol l ‐leucinol, and extracted from the fungus Trichoderma koningii, exhibits membrane‐modifying properties. We have synthesized by solution‐phase methods trikoningin KB II and several analogues with acyl chains of different length at the N‐ and C‐termini. Permeability measurements showed that an appropriate length of the linear acyl chain is a more important characteristic for the onset of significant membrane‐modifying activity than its position in the peptide chain. Copyright © 1999 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
10.
11.
Yao-Ling Qiu Mohamad B. Ksebati Jiri Zemlicka 《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):31-37
Abstract Synthesis of Z- and E-methylenecyclopropane analogues of adenosine 3 and 4 by alkylation of adenine with novel alkylating agent 5 is described. The E-isomer 4 is a substrate for adenosine deaminase. Compounds 3 and 4 were tested for antiviral activity against HCMV, HSV-1, HSV-2, EBV, VZV, HBV and HIV-1. 相似文献
12.
《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):779-781
Abstract A new method to introduce a benzyl group onto the 2′-OH of purine ribonucleoside is described. Thus, 6-chloropurine 3′-O-benzoylriboside and its 5′-O-trityl congener were condensed with benzyl alcohol using the Mitsunobu reaction to give the 2′-O-benzyl derivative. The yields were varied from 4.6 to 62.9% depending on the solvent. The product was converted to adenosine, indicating that the stereochemistry at C-2′ is retained. 相似文献
13.
《Nucleosides, nucleotides & nucleic acids》2013,32(2):145-151
Abstract A new method to introduce a benzyl group onto the 2′-OH of purine ribonucleoside is described. Thus, 6-chloropurine 3′-O-benzoylriboside and its 5′-O-trityl congener were condensed with benzyl alcohol using the Mitsunobu reaction to give the 2′-O-benzyl derivative. The yields were varied from 4.6 to 62.9% depending on the solvent used. The product was converted to adenosine, indicating that the stereochemistry at C-2′ is retained. 相似文献
14.
Philip J.M. van Galen Adriaan P. Ijzerman Willem Soudijn 《Nucleosides, nucleotides & nucleic acids》2013,32(2):275-291
Abstract The synthesis and A1 adenosine receptor affinity of some xanthine-7-ribosides is described. It appears that these compounds are A, receptor antagonists. The orientation of the ribose moiety, as determined by ′H-NMR spectroscopy and theoretical chemical calculations, is compared with the orientation of the ribose in the agonist adenosine. Implications for the syn vs anti modes of binding to the receptor are discussed. 相似文献
15.
Vanessa Plasse Ramos Pamela Gonçalves da Silva Pathise Souto Oliveira Natália Pontes Bona Mayara Sandrielly Pereira Soares Juliane de Souza Cardoso 《Biomarkers》2020,25(5):417-424
AbstractAim: This study investigated the effects of polar Butia odorata fruit extract on metabolic, inflammatory, and oxidative stress parameters in rats submitted to a hyperlipidaemia condition induced by tyloxapol.Methods: Animals were divided into 3 groups: saline, saline plus tyloxapol, and B. odorata extract plus tyloxapol. Animals were treated for 15?days with a saline solution or B. odorata fruit extract and after hyperlipidaemia was induced by tyloxapol.Results: Treatment with B. odorata extract reduced serum triglyceride, total cholesterol, C-reactive protein, and adenosine deaminase and butyrylcholinesterase activities when compared to the tyloxapol group. HDL-cholesterol and paraoxonase 1 activity were higher in B. odorata extract treated animals when compared to tyloxapol-treated animals. No differences were observed in hepatic oxidative stress parameters. Phenolic compounds present in B. odorata fruit extract were identified and quantified by LC-MS/MS.Conclusion: These findings indicated that phenolic rich B. odorata extract has hypolipidemic and anti-inflammatory effects in hyperlipidemic rats. 相似文献
16.
3,5‐Dinitrobenzoyl chloride was previously used for the preparation of (R)‐phenylglycinol‐ and (S)‐leucinol‐derived chiral stationary phases. In this study, 3,5‐bis(trifluoromethyl)benzoyl chloride, 2‐furoyl chloride, 2‐theonyl chloride, 10,11‐dihydro‐5H‐dibenzo[b,f]azepine‐5‐carbonyl chloride, diphenylcarbamoyl chloride, and 1‐adamantanecarbonyl chloride were used to prepare six new phenylglycinol‐derived chiral stationary phases (CSPs) and five new leucinol‐derived CSPs. Using these 11 CSPs, chiral separation of nine π‐acidic amino acid derivatives and five π‐basic compounds was performed, and the separation results were compared. An adamantyl‐derived CSP showed good separation. Chirality 28:276–281, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
17.
Koichiro Fukuoka Fuminori Suda Masahide Ishikawa Tsujiaki Hata 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):693-694
Abstract A bifunctional phosphorylating reagent, O-8-(5-chloroquinolyl) S-phenyl phosphorothioate (1) was employed for the synthesis of adenosine 5′-triphosphate (ATP) and diadenosine 5′-tetraphosphate (Ap4A) from adenosine 5′-phosphate (AMP) on a large scale. 相似文献
18.
Heng T. Duong Zhan-Guo Gao Kenneth A. Jacobson 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1507-1517
Residues of the second extracellular loop are believed to be important for ligand recognition in adenosine receptors. Molecular modeling studies have suggested that one such residue, Gln 167 of the human A 3 receptor, is in proximity to the C2 moiety of some adenosine analogs when bound. Here this putative interaction was systematically explored using a neoceptor strategy, i.e., by site-directed mutagenesis and examination of the affinities of nucleosides modified to have complementary functionality. Gln 167 was mutated to Ala, Glu, and Arg, while the 2-position of several adenosine analogs was substituted with amine or carboxylic acid groups. All compounds tested lost affinity to the mutant receptors in comparison to the wild type. However, comparing affinities among the mutant receptors, several compounds bearing charge at the 2-position demonstrated preferential affinity for the mutant receptor bearing a residue of complementary charge. 13, with a positively-charged C2 moiety, displayed an 8.5-fold increase in affinity at the Q167E mutant receptor versus the Q167R mutant receptor. Preferential affinity for specific mutant receptors was also observed for 8 and 12. The data suggests that a direct contact is made between the C2 substituent of some charged ligands and the mutant receptor bearing the opposite charge at position 167. 相似文献
19.
B. Danieli G. Lesma G. Palmisano D. Passarella B. Pyuskyulev 《Nucleosides, nucleotides & nucleic acids》2013,32(8):1667-1675
Abstract In vitro reaction of 17-OH tabersonine 2a and its 11-OMe analogue 2b with adenine, tri-O-acetyl adenosine, -guanosine and -cytidine under mild conditions, results in covalent adducts by electrophilic attack of reactive C-17 position of the alkaloids on the exocyclic nitrogen. 相似文献
20.
Yoshimitsu Yamazaki Hideo Suzuki Akira Kamibayashi Naoharu Watanabe Nobutaka Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(9):1945-1950
Five new derivatives of adenosine, N6-[(1-methylethyl)thiomethyl]-(1), N6-methyithiomethyl-(2), N6-phenylthiomethyl-(3), N6-[(3-amino-3-carboxypropyl)thiomethyl]-(4), and N6-[(2-amino-2-carboxyethyl)thiomethyl]adenosine (5), were synthesized and their cytokinin activity was tested in the Amaranthus betacyanin assay and the soybean callus growth.1, 2, and 3 were active in the former assay and all five compounds were active in the latter assay. The activities of the compounds were, however, weaker than those of the reference derivatives, in which Sulfides were replaced by methylenes, N6-isopentyl-, N6-n-propyl-, N6-benzyl-, and N6-(5-amino-5-carboxypentyl)adenosine. This fact indicates that the sulfide structure introduced into the N6-side chains had the effect of reducing cytokinin activity. 相似文献